>> Hi Alex,
>>     First of all thanks a lot for the reply.

>> On Wed, Mar 11, 2009 at 9:11 PM, Alex Gaynor <alex.gay...@gmail.com>wrote:

>>> On Wed, Mar 11, 2009 at 10:31 AM, Madhusudan C.S <madhusuda...@gmail.com
>>> > wrote:

>>>> Hi all,
>>>>      I wanted to fix this bug. I just went through the code to see what
>>>> was happening. For the same sample code given in the ticket, these were my
>>>> findings:

>>>> The schema generated looks like this and there is no issue with it:
>>>> CREATE TABLE "testapp_childmodel" (
>>>>     "parentmodel_ptr_id" integer NOT NULL PRIMARY KEY REFERENCES
>>>> "testapp_parentmodel" ("id"),
>>>>     "text" text NOT NULL
>>>> );
>>>> CREATE TABLE "testapp_parentmodel" (
>>>>     "id" integer NOT NULL PRIMARY KEY,
>>>>     "slug" varchar(50) NOT NULL
>>>> );
>>>> CREATE TABLE "testapp_parentmodel_links" (
>>>>     "id" integer NOT NULL PRIMARY KEY,
>>>>     "from_parentmodel_id" integer NOT NULL REFERENCES
>>>> "testapp_parentmodel" ("id"),
>>>>     "to_parentmodel_id" integer NOT NULL REFERENCES
>>>> "testapp_parentmodel" ("id"),
>>>>     UNIQUE ("from_parentmodel_id", "to_parentmodel_id")
>>>> );

>>>> CREATE INDEX "testapp_parentmodel_slug" ON "testapp_parentmodel"
>>>> ("slug");

>>>> I inserted test1, test2 and test3(all names being values of slug field)
>>>> to ParentModel and linked test1 and test3 to test2 through links field.
>>>> There seems to be no issues. Then I inserted testc1, testc2 and testc3 to
>>>> ChildModel and linked testc2 and testc3 to testc1 through inherited links
>>>> field. Now I can see only to links, i.e
>>>> I get these results in the interactive interpreter:

>>>> >>> from dummy.testapp.models import ParentModel, ChildModel
>>>> >>> c1 = ChildModel.objects.get(slug='testc1')
>>>> >>> c2 = ChildModel.objects.get(slug='testc2')
>>>> >>> c3 = ChildModel.objects.get(slug='testc3')
>>>> >>> c1.links.all()
>>>> []
>>>> >>> c2.links.all()
>>>> [<ParentModel: testc1>]
>>>> >>> c3.links.all()
>>>> [<ParentModel: testc1>]

>>>> This means only to links are being queried and not from links for the
>>>> inherited model. I just saw how the queries are working and these are the
>>>> queries constructed for c1, c2 and c3 respectively.

>>>> SELECT "testapp_parentmodel"."id", "testapp_parentmodel"."slug" FROM
>>>> "testapp_parentmodel" INNER JOIN "testapp_parentmodel_links" ON
>>>> ("testapp_parentmodel"."id" =
>>>> "testapp_parentmodel_links"."to_parentmodel_id") WHERE
>>>> "testapp_parentmodel_links"."from_parentmodel_id" = 4  LIMIT 21

>>>> SELECT "testapp_parentmodel"."id", "testapp_parentmodel"."slug" FROM
>>>> "testapp_parentmodel" INNER JOIN "testapp_parentmodel_links" ON
>>>> ("testapp_parentmodel"."id" =
>>>> "testapp_parentmodel_links"."to_parentmodel_id") WHERE
>>>> "testapp_parentmodel_links"."from_parentmodel_id" = 5  LIMIT 21

>>>> SELECT "testapp_parentmodel"."id", "testapp_parentmodel"."slug" FROM
>>>> "testapp_parentmodel" INNER JOIN "testapp_parentmodel_links" ON
>>>> ("testapp_parentmodel"."id" =
>>>> "testapp_parentmodel_links"."to_parentmodel_id") WHERE
>>>> "testapp_parentmodel_links"."from_parentmodel_id" = 6  LIMIT 21

>>>> From what I see the queries must be actually UNION of two queries which
>>>> fetch data both from, "from" and "to" fields in the
>>>> "testapp_parentmodel_links" table.It should look some thing like this, from
>>>> what I have understood:

>>>> SELECT "testapp_parentmodel"."id", "testapp_parentmodel"."slug" FROM
>>>> "testapp_parentmodel" INNER JOIN "testapp_parentmodel_links" ON
>>>> ("testapp_parentmodel"."id" =
>>>> "testapp_parentmodel_links"."to_parentmodel_id") WHERE
>>>> "testapp_parentmodel_links"."from_parentmodel_id" = 4  LIMIT 21
>>>> UNION
>>>> SELECT "testapp_parentmodel"."id", "testapp_parentmodel"."slug" FROM
>>>> "testapp_parentmodel" INNER JOIN "testapp_parentmodel_links" ON
>>>> ("testapp_parentmodel"."id" =
>>>> "testapp_parentmodel_links"."from_parentmodel_id") WHERE
>>>> "testapp_parentmodel_links"."to_parentmodel_id" = 4  LIMIT 21

>>>> Is this an elegant approach? If so can some one help me implement this?
>>>> I went through the code of QuerySet, Manager classes and other parts of
>>>> django.db.models. How to go about from here? I am very keen on fixing this
>>>> issue. Kindly help me.

>>> This looks like it may just be a symptom of
>>> http://code.djangoproject.com/ticket/10237 if I'm reading htis
>>> correctly.

>>> The problem looks very similar. I applied the patch and tried out. But it
>> doesn't seem to solve the problem at least for the data set I created as
>> above. So problem exists some where else too. Any pointers to where it might
>> be? (The query i.e being generated essentially remains the same even after
>> applying the supplied patch). But manager.symmetrical which used to return
>> False now correctly returns True.

> Sorry for sending this mail without testing. Did not notice that to test
> the patch the new data must be saved into the database or the old data
> updated. Was just trying with the existing data after applying the patch.
> The patch submitted in the ticket #10237 works fine for me.
> Thanks to justinlilly for the patch and thanks Alex for the help. Sorry for
> bothering you a lot.
> **

> --
> Thanks and regards,
>  Madhusudan.C.S

> Blogs at: www.madhusudancs.info
> Official Email ID: madhusu...@madhusudancs.info